I used 3M transfer film along with foam gasketing one can get locally.
The 3M stuff is much more resistant to heat and (hopefully) won't fail.
Other than separating the heater box plastic parts which can be a pain,
I would allow a weekend. There are a number of other items to address
while the dash is out.

Jon

On 11/7/2020 11:34 PM, Steve Williams wrote:
> Hi,
>
> I want to replace my front heater motor and the heater core.
>
> I've got a good video on removing the dash and it doesn't look that
> terrible.
> https://m.youtube.com/watch?v=KF66MnKOmbE&noapp=1
>
> How long would you estimate it takes to do it the first time?� lol
>
> I'm used to working on my van, wheel bearings, installing Propex &
> Lithium battery and various upgrades.
>
> I used to be scared to take my fridge out, but now I can do it in 20
> minutes with 0 stress :D
>
> I've got the clips to put the heater box back together, but I was
> wondering what people have used to seal the flaps inside the heater.��  I
> don't actually know what it looks like in there.
>
> Thanks,
> Steve Williams